LICHENOLOGY OF ICELAND 109 



on the unity where others see diversity of species, show a com- 

 prehension of the relationship of the lichens which, I believe, will 

 prove to contain many truths when once, at some future time, we 

 succeed, by experiments, in clearing up the limitation of the 

 species. But it should be borne in mind that, for the time being, 

 his systematic considerations (which are excellent according to my 

 opinion) are theories, pure and simple, which experiment alone 

 can set upon a firm foundation, and Deichmann Bra nth him- 

 self must have had a clear understanding of this. It is only to be 

 hoped that, one day, the necessary culture-experiments will be made, 

 which will eventually do that justice to his considerations, which 

 up to the present, has been too scanty. 



To the other group of investigators belong virtually all the 

 lichenologists of the present day - all those who so often establish 

 species upon quite slight peculiarities of structure in the individuals 

 considered. 



The inconveniences this causes with regard to the synonymy 

 of the lichens, is evident. The same name is sometimes used in a 

 limited and sometimes in a very wide sense. The same species is 

 sometimes referred to one, and sometimes to another genus. This 

 creates a confusion, which in several cases, is simply impossible 

 to reduce to order. 



In order to clear away the difficulties with regard to synonyms, 

 it has been the custom from the earliest times, to preserve in mu- 

 seums "original specimens," i. e. the specimens on which the author 

 has founded his species. This custom is very commendable, but 

 by no means so satisfactory, as we are frequently inclined to be- 

 lieve; the fact being that lichens alter rather essentially in the course 

 of time, frequently change colour, and alter their chemical reactions, 

 etc., to say nothing of the fact that the specimen may not be cut 

 up to ascertain the anatomical resemblance between it and other 

 specimens, the identity of which is wished to be ascertained; and 

 without such anatomical investigation, comparison is simply worth- 

 less in all difficult cases. This fact should be emphasized in order 

 to remove, once for all, the entire foundation built up under the 

 persistent worship of "original specimens." We must demand that 

 the author of the species should describe his species well, and not 

 only leave some gnawed or doubtful original specimen, which is 

 respected so highly that no one dares to dissect it, and thereby 

 deprive it of its importance, while often the very specimen proves, 



